nice chart; note safaricom modems can be had for 'free' - e.g. when you buy a laptop from them, or if you cash in your rewards points (just 2,000 bonga points)
Thanks for noting that bankelele. There's some other perks when you go outside the normal prepaid plans. I believe that some of the post-paid plans that require a deposit and 12month contract will also give you a free modem.